Y _0.08Sr _0.92Fe _xTi _1-xO _3-δ perovskite for solid oxide fuel cell anodes

A single phase perovskite Y _0.08Sr _0.92Fe _xTi _1-xO _3-δ (x = 0.05, 0.1,0 0.20, 0.25, 0.40, and 0.50) was fabricated at 1400 °C in air by a solid state reaction method and its electrical conductivity and electrochemical properties as an anode were investigated as a function of the Fe content. Doping with Y for Sr allowed the SrFe _xTi _1-xO _3-δ perovskite to be stable at 800 °C in a reducing atmosphere. At 900 °C, metallic Fe precipitated and the stability of the perovskite phase under a reducing atmosphere decreased as the Fe content increased. The conductivity of Y _0.08Sr _0.92Fe _xTi _1-xO _3-δ (x = 0.40) was greater than that of the x = 0.20 sample. The conductivity of Y _0.08Sr _0.92Fe _xTi _1-xO _3-δ was found to be 2 × 10 ^-1 Scm ^-1 at 800 °C in H ₂. Sintering the Y _0.08Sr _0.92Fe _xTi _1-xO _3-δ anode at 1200 °C was found to be optimum to obtain not only good interfacial adhesion, but also a fine grain structure. The Y _0.08Sr _0.92Fe _0.25Ti _0.75O _3-δ anode exhibited the lowest polarization resistance (0.7 and 1.8 Ωcm ² at 800 and 700 °C).